Tuesday, October 11, 2016

Changes in Playboy's women through 60 years

It has long been known that ideas about female attractiveness, and concern with body weight among young women, are closely related to exposure to mass media images (see the review by Spettigue & Henderson 2004). The print media are particularly involved in this issue, not least the so-called "men's magazines", such as Playboy. It therefore created a great deal of media interest when it was announced in October 2015 that Playboy would no longer feature nude centerfolds (known as Playmates).

Indeed, Playboy has often been claimed as a purveyor of the US society's image of the "ideal woman", although this is surely media exaggeration. Playboy, whether we love it or hate it, has simply portrayed females that the editors thought would sell magazines at the time. Nevertheless, the magazine's choice of models has been used in the professional medical and psychological literature as representative of a prevalent cultural idealization of an ultra-slender female body shape (eg. Garner et al. 1980; Wiseman et al. 1992; Szabo 1996; Spitzer et al. 1999; Katzmarzyk & Davis 2001; Pettijohn & Jungeberg 2004).

It therefore comes as no surprise that the magazine's database of model statistics was subjected to scrutiny in the online media after the 2015 announcement, particularly with regard to how things had changed during the magazine's 62 years. Sadly, some of this analysis was quite poor (eg. Playboy's image of the ideal woman sure has changed). Here, I try to correct this by presenting a more thorough study of the available data.

The data I have used covers all of the Playmates of the Month that have appeared in the US edition of the magazine since its inception. This is contained in a searchable version of the pmstats.txt file that has been maintained by Jim Dean, Johnny Corvin and Doug Ewell, as currently available on Peggy Wilkins' website. This file is an updated compilation of the so-called "vital statistics" of the Playmates from December 1953 to February 2016, inclusive, as reported in Playboy, sometimes supplemented from other available sources.

Note, especially, that the data are basically self-reported by the Playmates. Some of the information has been questioned at various times, notably where it seems to contradict the associated photographic evidence. As a reputable scientist, I should probably have personally checked all of this evidence, but I have not done so (you can do so yourself, based on whatever photos you can find on the internet). I have simply assumed that, at a minimum, the information presents whatever the Playmates thought was a desirable public image at the time of publication.

There are 753 records in the dataset, separately including twins and triplets appearing in the same magazine issue, as well as multiple appearances by the same woman in different issues. The data include: magazine issue month; Playmate name, birth date and birth location; height in inches and weight in pounds; breast, waist and hip dimensions in inches; and photographer name. From this information, for each Playmate I calculated their age at the time of publication, along with standard measurements for determining whether a body is healthy or not: Body Mass Index (BMI), for body size (ie. underweight, normal weight, overweight, obese), and Waist to Hip Ratio (WHR), for body curvaceousness.

Analysis

As is usual in this blog, the data can be summarized using a phylogenetic network as a form of exploratory data analysis (see How to interpret splits graphs).

I first range-standardized the data (so that all of the measurements are compared on the same scale), and log-transformed the BMI and WHR measurements (because otherwise these ratios will have non-linear relationships to the other variables). I then used the manhattan distance to calculate the similarity of the different publication years and birth locations, based on the Playmates' body dimensions. This was followed by a neighbor-net analysis to display the between-year and the between-location similarities as two phylogenetic networks.

The network of relationships among the years is shown first. Years that are closely connected in the network are similar to each other based on the body dimensions of their Playmates, and those that are further apart are progressively more different from each other.

Click to enlarge

The network shows that there has been a strong and consistent change in Playmate age, size and shape through time. In the graph there is a simple gradient through time form top-right to bottom-left — the 1950s and 1960s are intermingled at the top, with the 1970s below them, the 1980s and 1990s below that, and the 2000s and 2010s intermingled at the bottom.

So, it will be worth looking at time graphs of the individual measurements. Let's start with age.

This does not show a particularly consistent trend, but the average age of the models does increase from 21 to 24 years from beginning to end of the time period.

The next graph shows that the reported height of the Playmates also increases across the 62 years, by 2.5" on average. There is almost no change in average weight across the decades (and so the graph is not shown).

However, far more notable is the relationship between height and weight, as expressed by the BMI, which is shown in the next graph. This does not show a linear trend at all, but a distinctly curved one. That is, the size of Playmates definitely changed through time, becoming thinner for the first 40 years, but then thickening up again for the next 20 years.

This trend has not been discussed in the professional literature, as far as I can determine, perhaps because previous assessments have been based only on a relatively short period of time, not the full 6 decades. Note that the bottom point of the curve occurs in c. 1997, and that by 2016 the BMI measurements had returned to the 1975 level (40 years earlier). I wonder whether they would return to the 1950s level in another 20 years?

More importantly, given that Playmates are to one degree or another reflecting a contemporary societal image of a desirable woman, we can note that 48% of these models are classified as being underweight. The lower limit of a healthy BMI is 18.5, as shown in the next graph, which also shows the boundaries between Mild thinness (17-18.5), Moderate thinness (16-17) and Severe thinness (<16).

Clearly, during the period 1975-1995 the vast majority of the models reported being underweight, while in the 1950s and 1960s very few of them did. This situation has improved recently, with roughly a half being underweight during the past 20 years. Also, several of the reported body sizes are very unhealthy. However, perhaps the BMI values below 16 are unreliable, in the sense that such a person is not likely to be very photogenic.

We can now move on to the circumferences of the models. The next graph shows the time trend for the reported circumference at breast level. This shows the biggest and most consistent change of all, with a dramatic reduction in bustiness.

Indeed, chest sizes of >36" have hardly been reported since the start of 1990, and yet in the early years a buxom 36-24-36 figure was the most common claim by the Playmates. Interestingly, very few of the models have claimed a chest size of 33" (as opposed to 32" or 34"); is this some sort of superstition?

The other large and consistent change in circumference is for waist size, as shown in the next graph. This shows the opposite trend, with an increase in average reported size of 2" across the 60 years.

There was a slight but not consistent reduction in hip circumference during time (and so the graph is not shown). This means that the WHR, the measure of curvaceousness, changed greatly through time, as shown in the next graph. So, with the waists reportedly becoming larger, there was apparently a very large reduction in the curvaceousness of the models through time.

Note that the reduction in BMI was apparently achieved in spite of an increase in waist size — the BMI reduction seems to be related to the increase in average reported height without an increase in weight, and partly to the decrease in chest size.

When combined with the reduction in breast circumference, this means that the Playmates of the 21st century have been a very different shape from those of the mid 20th century. They were taller, with smaller breasts and larger waists, and thus had fewer curves.

We can end this discussion by considering where these Playmates were born. Most of them reported being born in the USA (83%). This means that we can consider how the various states compare in producing nude models. Obviously, more models are likely to come from the most populous states, and so we need to standardize the data by dividing by the population size of each state (as estimated for 2015 in Wikipedia), to yield the number of Playmates per million people in each state.

Apparently, Hawaii and California are more likely than the other states to produce models who are prepared to take their clothes off in public, while Delaware and Vermont have not yet done so, at least as far as Playboy is concerned. The apparently large value for Washington DC represents only 2 models from a relatively small population.

We can also consider whether the dimensions of the models vary in any consistent way between the states. This can be done with a phylogenetic network, as discussed above. In the following network, states that are closely connected are similar to each other based on the body dimensions of their Playmates, and those that are further apart are progressively more different from each other.

There appear to be no consistent patterns here.

So, we can finish by considering the countries from which the remaining 17% of the models originated. Once again, the data are standardized, to yield the number of Playmates per million people in each country (or province, for Canada). The apparently large value for Malta represents one set of twins from a relatively small population.

There have been a relatively large number of models from Scandinavia (Norway, Denmark and Sweden). This presumably represents the number of females whose body shape matches the image required by the Playboy editors, as much as the willingness of Scandinavians to disrobe publicly. However, it is notable that the rate of models from Norway is double those for Denmark and Sweden.

2 comments:

I'm reminded of a theory I've seen floating around for why, in highly sexualized and nude/semi-nude paintings/statues pre-1900, the women are to modern eyes so pudgy or 'Rubenesque': some pudginess was, like pale skin, a marker of high socioeconomic status and being well fed ('fat cats'), setting the upperclass apart from the thin impoverished masses. Nowadays it's the opposite: the poor are more obese than the rich, as the flood of cheap calories and the removal of physical exertion from daily life make it far easier to be fat than thin. So if in old artwork, the rich and desirable higher status women were associated with plumpness, that same theory would predict that if the class/fat association reversed, then sexualized women will also tend to reverse. This would immediately explain the Playboy trends: increasing height and constant total weight means spreading the same amount of flesh over a larger body, producing lower BMI and more apparent thinness and visible musculature (and a better chance of being selected as a Playboy model), and since body fat/BMI and breast size are correlated phenotypically & genetically, this would simultaneously select the models for smaller breast size (only partially offset by the availability of breast implants).

This explanation makes a lot of testable predictions. Some of these relationships are nonlinear, so that might provide a test of it compared to other models. A SEM predicting a decrease in body fat/BMI affecting the height/waist/total weight should fit better than treating them as unrelated. This would predict that body fat percentage of models should decrease over time and decrease as obesity rates in America (the primary customer base) increase; this wouldn't be in the self-reported stats but one could probably have human raters (blinded to the temporal trend hypothesis, of course) go through the centerfold photos to rate on apparent body fat composition and muscularity. It's been a long time since I looked at a Playboy but didn't they also have some textual filler describing the models in general with nonsense about hobbies and whatnot? I would guess that plotting word use over time might also be revealing - early on, more emphasis on terms like 'curves' and 'soft' and later on more use of terms like 'athletic' and 'svelte'. The nationality breakdown could be checked by considering whether obesity rates in the original country predict success of models from it - if Sweden manages to control obesity rates while American obesity rates increase, the number of Swedish models should increase.

You suggested correlation between social status and obesity makes good sense; and I seem to remember that this issue is briefly touched on in some of the papers I cite above.

Collecting data for your predictions might be tricky, of course. Playboy certainly has descriptive text for each model, which is where the data I used come from. I am not sure how reliable is this self-reported information, or how easy it is to the access the rest of the text. There might, however, be volunteers to go through the pictures and make quantitative assessments of the figures! Obesity rates in different countries, and even states of the USA, are readily available; and, indeed, Scandinavians are much more physically active than many other cultures, and so their obesity rates are low.